A cascade is a 
-action or 
-action. A cascade and a single
map 
are essentially the same, but the term "cascade" is preferred by many Russian
authors.
Cascade
See also
Action, FlowExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Cascade." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Cascade.html